mtd: spinand: add OTP support

The MTD subsystem already supports accessing two OTP areas: user and
factory. User areas can be written by the user.

This patch provides the SPINAND_FACT_OTP_INFO and SPINAND_USER_OTP_INFO
macros to add parameters to spinand_info.
To implement OTP operations, the client (flash driver) is provided with
callbacks for user area:
    .read(), .write(), .info(), .lock(), .erase();
and for factory area:
    .read(), .info();

Signed-off-by: Martin Kurbanov <mmkurbanov@salutedevices.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>